Tup, the river. Flows through the Ak-Suu and Tyup areas. Originates on the northern slope of the ridge Teskey Ala-Too and empties into the Gulf of Tyup Lake Issyk-Kul. The river is 120 km and a catchment area of 1180 km ². The largest river of the Issyk-Kul. Major tributaries are the Ken-Suu, Chong-Tash, Koochi, Taldy-suu, Shaty, Korumdu and others. The river has the lowest average height of the catchment, resulting in a pool is less than the most common modern glaciers. The main source of supply - melted snow and rainwater. It has stretched spring floods. The annual precipitation is 880 mm. Maximum flow occurs in the month of May. Average annual water consumption 10.6 cu / m per second.